JP5855401B2 - Manufacturing method of fiber reinforced thermoplastic resin molded article - Google Patents

Description

The present invention relates to a fiber-reinforced thermoplastic resin molded article of manufacture how.

A fiber reinforced thermoplastic resin composed of a reinforced fiber and a thermoplastic resin is a material that is molded into a desired molded product by press molding using a mold composed of a female mold and a male mold, and is widely used.
In such a fiber reinforced thermoplastic resin, a continuous fiber reinforced thermoplastic resin layer using continuous fibers as the reinforced fibers, and a discontinuous fiber reinforced heat using discontinuous fibers having a length of, for example, 5 to 100 mm as the reinforced fibers. Press molding of a sheet material laminated with a plastic resin layer is also performed. Such a sheet material has both mechanical properties and shapeability, and therefore, for example, automobiles such as front subframes, rear subframes, front pillars, center pillars, side members, cross members, side sills, roof rails, and propeller shafts. It is suitably used for molding parts, subsea oil field pipes, electric cable cores, printing press rolls and pipes, robot forks, aircraft primary structural materials, secondary structural materials, and the like.

As a method for press-molding a fiber-reinforced thermoplastic resin using a mold, for example, Patent Document 1 discloses a mold in which a gap is not substantially formed between both molds outside a cavity when the mold is closed. A method is described in which a mold is used to fill a cavity with a thermoplastic resin sheet containing reinforcing fibers (discontinuous fibers) having a length of 3 to 50 mm while filling the cavity.
On the other hand, in Patent Document 2, when a mold is closed, a mold having a gap of approximately the same thickness as the molded product is formed between both molds outside the cavity, and the length is 3 to 50 mm. A method for forming a thermoplastic resin sheet containing reinforcing fibers (discontinuous fibers) is described.

Japanese Patent Laid-Open No. 10-100194 Japanese Patent Application Laid-Open No. 07-32465

However, when a sheet material including a continuous fiber reinforced thermoplastic resin layer and a discontinuous fiber reinforced thermoplastic resin layer is used as a molding material, press molding is performed using the mold described in Patent Documents 1 and 2, as follows. There was a problem.
That is, the discontinuous fiber reinforced thermoplastic resin layer of the sheet material has short reinforced fibers and high fluidity, and therefore flows and spreads in the cavity during press molding, and behaves so as to fill the cavity. Therefore, the area of the discontinuous fiber reinforced thermoplastic resin layer set on the cavity surface before closing the mold is set to be smaller than the area covering the entire cavity surface in consideration of such expansion. There are many cases. On the other hand, since the continuous fiber reinforced thermoplastic resin layer includes continuous fibers, the fluidity is low, and the continuous fiber reinforced thermoplastic resin layer hardly flows and spreads in the cavity. Therefore, the area of the continuous fiber reinforced thermoplastic resin layer set on the cavity surface before closing the mold is larger than the area covering the entire cavity surface with a margin, and the peripheral edge extends outward from the cavity surface. It is set to the size to be.

  However, in the mold described in Patent Document 1, when the mold is closed, a gap is not substantially formed between both molds outside the cavity. Therefore, when the laminated sheet including the continuous fiber reinforced thermoplastic resin layer and the discontinuous fiber reinforced thermoplastic resin layer is placed in the cavity and the mold is closed, the peripheral portion of the continuous fiber reinforced thermoplastic resin layer is the cavity. As a result, the mold may not be opened.

  On the other hand, in the mold described in Patent Document 2, when the mold is closed, a gap having the same thickness as that of the molded product is formed outside the cavity. Therefore, unlike the case where the mold of Patent Document 1 is used, there is no problem that the continuous fiber reinforced thermoplastic resin layer is firmly sandwiched and the mold cannot be opened. However, the discontinuous fiber reinforced thermoplastic resin layer having high fluidity flows out from the gap, and the resulting molded product has a problem that a large amount of burrs are generated due to solidification of the outflow.

  The present invention has been made in view of the above circumstances. When a sheet material obtained by laminating a continuous fiber reinforced thermoplastic resin layer and a discontinuous fiber reinforced thermoplastic resin layer is press-molded with a mold, there is a problem with the mold. It is an object of the present invention to provide a method for producing a fiber-reinforced thermoplastic resin molded article that can be opened without any problem and can suppress the occurrence of burrs, a mold used in the production method, and a molded article produced by the production method. To do.

The mold used in the present invention is formed by press-molding a sheet material in which a discontinuous fiber reinforced thermoplastic resin layer is laminated on at least a part of one surface of a continuous fiber reinforced thermoplastic resin layer, thereby producing a fiber reinforced thermoplastic resin molded product. A frame-shaped weir for preventing the discontinuous fiber reinforced thermoplastic resin layer from flowing out of the cavity when the mold is closed, on the outer peripheral edge of the cavity, The continuous fiber reinforced thermoplastic resin layer is provided while forming a gap that extends out of the cavity. That is, the discontinuous fiber reinforced thermoplastic resin is provided at the outer peripheral edge of the cavity when the mold is closed. A frame-like weir is provided to prevent the layer from flowing out of the cavity, and when the mold is closed, between the front end surface of the weir and the outer peripheral edge of the cavity surface facing this is before press molding. The continuation of Reinforced Kanetsu wherein the 80% to 120% of the gap height of the thickness of the thermoplastic resin layer is set to be formed.
The height of the mold gap is preferably adjustable .
The width of the dam portion of the mold is preferably 1 to 20 mm.

The method for producing a fiber-reinforced thermoplastic resin molded article of the present invention includes a molding step of press-molding the sheet material using the mold of the present invention.
The reinforcing fibers contained in the discontinuous fiber reinforced thermoplastic resin layer preferably have a volume content of 20 to 60% and a length of 5 to 100 mm.
The discontinuous fiber reinforced thermoplastic resin layer is formed by cutting a tape-like material having a thickness of 30 to 300 μm and a width of 5 to 30 mm in which continuous reinforcing fibers are aligned in one direction and impregnated with a thermoplastic resin into a length of 5 to 100 mm. The chopped tape is preferably made of a material obtained by dispersing the chopped tape and hot press molding.
The reinforcing fiber contained in the continuous fiber reinforced thermoplastic resin layer preferably has a volume content of 30 to 70%.
The continuous fiber reinforced thermoplastic resin layer is a laminated material in which continuous reinforcing fibers are aligned in one direction and a unidirectional sheet material impregnated with a thermoplastic resin is laminated, and continuous reinforcing fibers are aligned in one direction. It consists of a cloth material formed by weaving a tape-like material impregnated with a thermoplastic resin, and one or more selected from the group consisting of a cloth material in which a reinforcing fiber fabric is impregnated with a thermoplastic resin and is formed by hot press molding. preferable.
In the molding step, it is preferable that the continuous fiber reinforced thermoplastic resin layer of the sheet material is attached to an elastic body provided in a frame, and the press molding is performed while applying tension to the continuous fiber reinforced thermoplastic resin layer.
It is preferable to have a preheating step of preheating the discontinuous fiber reinforced thermoplastic resin layer and the continuous fiber reinforced thermoplastic resin layer separately in an infrared heating furnace before the molding step.
Or it is preferable to have the preheating process which piles up the said discontinuous fiber reinforced thermoplastic resin layer and the said continuous fiber reinforced thermoplastic resin layer, and preheats with an infrared heating furnace before the said shaping | molding process.
In the preheating step, it is preferable that the continuous fiber reinforced thermoplastic resin layer is attached to an elastic body provided in the frame and preheated while applying tension to the continuous fiber reinforced thermoplastic resin layer.
The fiber-reinforced thermoplastic resin molded article of the present invention is manufactured by the manufacturing method of the present invention.

  According to the present invention, when a sheet material in which a continuous fiber reinforced thermoplastic resin layer and a discontinuous fiber reinforced thermoplastic resin layer are laminated is press-molded with a mold, the mold can be opened without any problem. It is possible to provide a method for producing a fiber-reinforced thermoplastic resin molded product capable of suppressing the occurrence of the above, a mold used in the production method, and a molded product produced by the production method.

It is a perspective view which shows an example of the sheet material used by this invention. It is a perspective view which shows an example of the metal mold | die of this invention. It is a longitudinal cross-sectional view which follows the A-A 'line of the metal mold | die of FIG. It is a longitudinal cross-sectional view which shows the state which closed the metal mold | die of FIG. It is a top view which shows roughly the state which set the sheet material on the lower metal mold | die in implementation of a formation process. It is a longitudinal cross-sectional view explaining a formation process. It is a longitudinal cross-sectional view explaining a formation process. It is a perspective view of the fiber reinforced thermoplastic resin molded product obtained at the formation process. It is a perspective view after trimming the molded article of FIG. It is a longitudinal cross-sectional view which shows another example of the sheet material used by this invention. It is a longitudinal cross-sectional view which shows the formation process of the sheet material of FIG. It is a perspective view which shows the state which attached the continuous fiber reinforced thermoplastic resin layer of the sheet material to the frame. It is a longitudinal cross-sectional view explaining the shaping | molding process performed with attaching a continuous fiber reinforced thermoplastic resin layer to a frame.

Hereinafter, the present invention will be described in detail.
(Sheet material)
FIG. 1 is a perspective view showing an example of a sheet material press-molded by the mold of the present invention. In this example, the sheet material 10 includes a rectangular discontinuous fiber reinforced thermoplastic resin in a part including the center on one side of a rectangular continuous fiber reinforced thermoplastic resin layer (hereinafter sometimes referred to simply as a continuous fiber layer) 11. It is a sheet-like material in which layers (hereinafter, sometimes referred to as discontinuous fiber layers) 12 are laminated. By press-molding the sheet material 10 with a mold, a three-dimensional fiber-reinforced thermoplastic resin molded product (hereinafter sometimes simply referred to as a molded product) is produced.

  The discontinuous fiber layer 12 is a layer in which, for example, reinforcing fibers cut to a length of 5 to 100 mm are dispersed in a thermoplastic resin. The reinforcing fibers may be dispersed in the state of filaments that are opened one by one, or may be dispersed in a bundle consisting of a large number of reinforcing fiber filaments. The opened filaments and bundles of fibers are preferably dispersed pseudo-isotropically randomly in the thermoplastic resin. Here, random dispersion means a bundle of a large number of reinforcing fiber filaments, a state in which reinforcing fibers are dispersed without specific orientation, and individual reinforcing fiber filaments without specific orientation. Including any of the states that are dispersed.

  As a specific form of the discontinuous fiber layer 12, a tape-like material having a thickness of 30 to 300 μm and a width of 5 to 30 mm in which continuous reinforcing fibers are aligned in one direction and impregnated with a thermoplastic resin has a length of 5 to 100 mm. It is cut into a chopped tape, the chopped tape is randomly dispersed in the mold, and the mold is molded by hot press molding in which the inside of the mold is heated, pressurized, and cooled.

  The volume content of reinforcing fibers in the discontinuous fiber layer 12 (measured according to JIS K 7052 and K 7075) is preferably 20 to 60%, and the length of the reinforcing fibers is preferably 5 to 100 mm. When the volume content of the reinforcing fibers is 20% or more, the discontinuous fiber layer 12 can exhibit physical properties derived from the reinforcing fibers. When the volume content of the reinforcing fibers is 60% or less, the fluidity of the discontinuous fiber layer 12 is maintained. When the reinforcing fiber length is 5 mm or more, the physical properties of the molded product are excellent, and when the reinforcing fiber length is 100 mm or less, the fluidity during press molding of the discontinuous fiber layer 12 is excellent.

  The thermoplastic resin contained in the discontinuous fiber layer 12 is not particularly limited, and polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polystyrene, ABS resin, acrylic resin, vinyl chloride, polyamide 6 and the like. Polyamide, polycarbonate, polyphenylene ether, polyether sulfone, polysulfone, polyether imide, polyketone, polyether ketone, polyether ether ketone and the like can be used. Moreover, the modified body of these each resin may be used, and multiple types of resin may be blended and used. Further, the thermoplastic resin may contain various additives, fillers, colorants and the like.

  Examples of the reinforcing fibers contained in the discontinuous fiber layer 12 include glass fibers, carbon fibers, and aramid fibers.

The continuous fiber layer 11 is a layer formed from a thermoplastic resin and continuous fibers, and the continuous fiber refers to an uninterrupted layer in the continuous fiber layer 11. Since the continuous fiber layer 11 includes such continuous fibers, the physical properties are extremely excellent.
As a specific form of the continuous fiber layer 11, a laminated material in which continuous reinforcing fibers are aligned in one direction and a unidirectional sheet material impregnated with a thermoplastic resin is laminated at an arbitrary angle and an arbitrary number of layers; One selected from the group consisting of: a cloth material obtained by weaving a tape-like material in which the reinforced fibers are aligned in one direction and impregnated with a thermoplastic resin; a cloth material obtained by impregnating a reinforcing fiber fabric with a thermoplastic resin; What carried out the hot press molding of the above is illustrated preferably. Examples of the cloth weaving method include plain weave, twill weave, satin weave, and triaxial weave.

The volume content of reinforcing fibers in the continuous fiber layer 11 is preferably 30 to 70%. When the volume content of the reinforcing fibers is 30% or more, the continuous fiber layer 11 can exhibit physical properties derived from the reinforcing fibers. If the volume content of the reinforcing fibers is 70% or less, the press formability of the continuous fiber layer 11 can be maintained.
The thermoplastic resin and the reinforcing fiber contained in the continuous fiber layer 11 can be selected from those exemplified for the discontinuous fiber layer 12, for example. The thermoplastic resin and the reinforcing fiber included in the continuous fiber layer 11 and the discontinuous fiber layer 12 may be the same or different.

(Molding process)
FIG. 2 is a view showing an example of the mold of the present invention, and FIG. 3 is a longitudinal sectional view taken along the line AA ′ of FIG. The mold 20 of this example includes an upper mold (male mold) 21 and a lower mold (female mold) 22 as a pair of molds that move relatively close to and away from each other, and has no shear edge.
The shear edge is a portion where the gap between the upper mold and the lower mold is set to about 0.05 mm on the outside of the cavity, and the outflow of the fiber reinforced thermoplastic resin to be molded out of the cavity is suppressed. It is provided for the purpose. The outside of the cavity means the outside in the direction perpendicular to the direction of relative movement of the pair of molds.

  In the illustrated mold 20, the upper mold 21 is attached to the upper mold support plate 23, and the lower mold 22 is attached to the lower mold support plate 24. Then, as a restricting means for restricting the degree of approach between the upper mold 21 and the lower mold 22, four sets of stoppers erected on the upper mold support plate 23 and the lower mold support plate 24 so as to face each other. S is provided. When the upper mold support plate 23 and the lower mold support plate 24 approach each other to a predetermined distance, the ends of the stoppers S facing each other come into contact with each other and restrict further approach. The state where the tips of the stoppers S are in contact with each other and the upper mold support plate 23 and the lower mold support plate 24 approach each other up to a predetermined distance is a state where the mold 20 is closed. By closing the mold 20 in this way, a cavity is formed by the cavity surface 21a of the upper mold 21 and the cavity surface 22a of the lower mold 22, and the sheet material 10 is press-molded into a shape along the cavity.

And in the metal mold | die 20 of this example, the frame-shaped dam part 30 which consists of the same metal as the metal mold | die 20 is formed in the outer periphery of a cavity. The dam portion 30 is provided over the entire outer periphery of the cavity so that the discontinuous fiber layer 12 does not flow and flow out of the cavity when the mold 20 is closed as shown in FIG. It is a dam. The weir 30 in this example is formed so as to protrude downward at the outer peripheral edge of the cavity surface of the upper mold 21.
The height h1 of the weir 30 is such that when the mold 20 is closed, a gap C is formed between the tip surface (lower surface) of the weir 30 and the outer peripheral edge of the cavity surface 22a of the lower mold 22. Is set to From the gap C, the continuous fiber layer 11 extends out of the cavity when the mold 20 is closed. The height h1 of the weir 30 corresponds to the thickness of the discontinuous fiber layer 12 after press molding, and the height h2 of the gap C substantially corresponds to the thickness of the continuous fiber layer 11 as described in detail later. In addition, the thickness of the continuous fiber layer 11 hardly changes before and after pressing.
Thereby, when the mold 20 is closed, the continuous fiber layer 11 extends from the gap C and is not firmly sandwiched between the upper mold 21 and the lower mold 22 outside the cavity. Further, since the gap C is closed by the continuous fiber layer 11, combined with the effect of the weir 30, the outflow of the discontinuous fiber layer 12 out of the cavity is also suppressed.
Here, the “height” of the weir 30 and the gap C is measured along the direction of relative movement of the pair of molds.

  In this example, as shown in FIG. 5, the size (vertical La, horizontal Wa) of the discontinuous fiber layer 12 constituting the sheet material 10, the size (vertical Lb, horizontal Wb) of the continuous fiber layer 11, the weir The outer edge size (vertical Lm, horizontal Wm) of the portion 30 satisfies the relationship La <Lm <Lb, Wa <Wm <Wb. Thereby, when the mold 20 is closed, the discontinuous fiber layer 12 is prevented from flowing out of the cavity by the weir 30 and the continuous fiber layer 11 extends from the gap C to the outside of the cavity.

  When press-molding the sheet material 10 of FIG. 1 using such a mold 20, first, as shown in FIG. 6, in this example, the upper mold 21 is raised and the mold 20 is opened, The sheet material 10 is set on the lower mold 22. In this mold 20, a dam portion 30 is provided in an upper mold 21, and a gap C is formed below the dam section 30. Therefore, the sheet material 10 is set so that the upper side becomes the discontinuous fiber layer 12 from which the outflow is prevented by the weir 30 and the lower side becomes the continuous fiber layer 11 extending from the gap C.

Next, as shown in FIG. 7, the upper mold 21 is lowered until the tips of the opposing stoppers S come into contact with each other, the mold 20 is closed, and the sheet material 10 is press molded (molding process).
Here, the mold 20 of this example is provided with a weir 30, and when the mold 20 is closed, a gap C is formed between the tip surface of the weir 30 and the lower mold 21. Is done. Therefore, when the mold 20 is closed in this way in the molding process, the peripheral edge of the continuous fiber layer 11 extends out of the cavity from the gap C and is firmly sandwiched between the upper mold 21 and the lower mold 22. It will not be. Therefore, there is no problem that the mold cannot be opened when the continuous fiber layer is firmly sandwiched.
On the other hand, the discontinuous fiber layer 12 flows in the cavity because the contained reinforcing fiber is short and has high fluidity. However, the weir 30 is provided on the outer peripheral edge of the cavity, and the gap C is a continuous fiber layer. Since it is blocked by 11, it does not flow out of the cavity. Therefore, almost no burrs due to solidification of the outflow are generated in the obtained molded product.

  After such a molding process, the upper mold 21 is raised to open the mold, and the molded product 40 ′ shown in FIG. 8 is taken out. Then, if necessary, by trimming unnecessary portions such as the continuous fiber layer 11 extending from the gap C, the molded product 40 as the final product shown in FIG. 9 can be obtained.

  As described above, the height of the gap C is set so as to substantially correspond to the thickness of the continuous fiber layer 11, and specifically, set to 80 to 120% of the thickness of the continuous fiber layer 11. Is preferable, and is more preferably set to 80 to 100%. If it is 80% or more and 100% or less, the outflow of the discontinuous fiber layer 12 to the outside of the cavity can be almost completely suppressed, and if it exceeds 100% and 120% or less, the outflow of the discontinuous fiber layer 12 is extremely small. Can be suppressed.

Moreover, it is preferable that the height of the gap C is configured to be adjustable. The height of the gap C is determined by the height of the stopper S and the height of the dam portion 30. Therefore, the height h2 of the gap C can be appropriately adjusted according to the thickness of the discontinuous fiber layer 12 by configuring the stopper S and the weir 30 so that the height can be adjusted.
As a method for adjusting the height of the stopper S of the upper mold 21, for example, a height adjusting plate is attached to the lower surface of the stopper S, between the stopper S and the upper mold support plate 23, or both of them. There is a way to increase the height. Similarly, as a method of adjusting the height of the stopper S of the lower mold 21, a height adjusting plate is similarly provided on the upper surface of the stopper S, between the stopper S and the lower mold support plate 24, or both of them. There is a way to attach and increase the height.
Further, as a method for adjusting the height of the dam portion 30, the dam portion itself can be removed and a dam portion having a different height can be reattached, or between the dam portion and the upper die 21 and the lower die 22. Further, there is exemplified a method of increasing the height of the weir portion according to the thickness of the inserted plate in a structure in which a metal plate for height adjustment can be inserted.

  The width of the weir 30 (width of the vertical surface with respect to the extending direction of the weir) Ws is preferably 1 to 20 mm. When the width Ws is 1 mm or more, the outflow of the discontinuous fiber layer 12 can be effectively suppressed. On the other hand, when the width Ws is 20 mm or less, the mold 20 can be opened without any problem even if the weir 30 bites into the continuous fiber layer 11 and the weir 30 and the continuous fiber layer 11 are in close contact with each other.

  In the above example, the case where the sheet material 10 in which the discontinuous fiber layer 12 is laminated only on one side of the continuous fiber layer 11 is press-molded is shown. However, as shown in FIG. The sheet material 50 in which the discontinuous fiber layer 12 is laminated on a part including the center can also be press-molded.

For press molding of the sheet material 50 in FIG. 10, for example, a mold 60 in FIG. 11 is used. In this mold 60, weir portions 30 are provided not only on the outer peripheral edge of the cavity surface 21 a of the upper mold 21 but also on the outer peripheral edge of the cavity surface 22 a of the lower mold 22, and when the mold 60 is closed, A gap C in which the continuous fiber layer 11 extends out of the cavity is formed between the upper and lower weir portions 30. By using such a mold 60, when the mold 60 is closed, the weir 30 provided in the upper mold 21 suppresses the outflow of the discontinuous fiber layer 12 laminated on the upper surface of the continuous fiber layer 11. The weir 30 provided in the lower mold 22 suppresses the outflow of the discontinuous fiber layer 12 laminated on the lower surface of the continuous fiber layer 11. On the other hand, the continuous fiber layer 11 extends out of the cavity from the gap C between the dam portions 30.
As described above, even when the sheet material 50 having the configuration shown in FIG. 10 is used, the use of the mold 60 having the configuration shown in FIG. The problem that the peripheral part of the fiber layer 11 is sandwiched between the upper mold and the lower mold and the mold cannot be opened can be prevented.

  The press molding conditions in the molding process depend on the type of thermoplastic resin used for the discontinuous fiber layer 12 and the continuous fiber layer 11, but for example, the set temperature of the molds 20, 60 (the melting point of the resin or the glass It is preferable that the transition temperature is −100) ° C. to (the melting point or glass transition temperature of the resin) ° C., and the molding pressure is 3.0 to 30 MPa and the holding time is 0.5 to 10 minutes.

In the molding step, the continuous fiber layer 11 of the sheet materials 10 and 50 is attached to an elastic body provided in the frame in order to suppress generation of wrinkles of the continuous fiber layer 11 in the obtained molded product. It is preferable to press-mold the sheet materials 10 and 50 while applying tension to the fiber layer 11.
Specifically, for example, as shown in FIG. 12, clamps 71 are attached to a total of eight locations of the four apexes of the continuous fiber layer 11 and the central portion of the four sides, while the inner four corners of the frame 72, the vertical frame, Clamps 73 are attached to a total of eight places with the inner central portion of the horizontal frame, and one coil spring 74 is provided for each of the corresponding clamps 71 and 73, so that the sheet material 10 including the continuous fiber layer 11 is contained in the frame 72. Attach to. Then, as shown in FIG. 13, the sheet material 10 is placed on the cavity surface of the lower mold 22 together with the frame body 72, and then press-molded.

  In this example, by arranging the coil springs 74 at approximately equal intervals at eight positions on the peripheral edge of the continuous fiber layer 11, the outward tension is applied to the entire continuous fiber layer 11 as uniformly as possible. However, the number of coil springs 74 used and the location of attachment can be appropriately set according to the shape of the continuous fiber layer 11, the shape of the frame 72, the shape of the molded product to be obtained, and the like. Further, the elastic body is not limited to the coil spring 74, and a spring other than the coil spring, a heat-resistant rubber body, and the like can be used. It can set suitably according to the shape etc.

(Preheating process)
Prior to the forming step, a preheating step of preheating the sheet materials 10 and 50 is preferably performed, and it is more preferable to perform a preheating step using an infrared heating furnace. When the preheating step is performed by infrared heating, the inside of the sheet materials 10 and 50 can be heated uniformly, which is preferable. The set temperature of the preheating step depends on the type of thermoplastic resin used for the discontinuous fiber layer 12 and the continuous fiber layer 11, but the melting point or glass transition temperature of the resin to (the melting point or glass transition temperature of the resin +150 ) Temperature in degrees Celsius. The holding time is 1 to 10 minutes.

In the preheating step, the discontinuous fiber layer 12 and the continuous fiber layer 11 may be preheated separately in an infrared heating furnace, or after the discontinuous fiber layer 12 and the continuous fiber layer 11 are stacked, You may preheat. In the case where the discontinuous fiber layer 12 and the continuous fiber layer 11 are separately preheated, these may be stacked after the preheating to perform the molding step.
Also in the preheating step, it is preferable to preheat the continuous fiber layer 11 while applying tension. Thereby, the deformation | transformation of the continuous fiber layer 11 in the middle of the transfer from a preheating process or a preheating process to a shaping | molding process can be suppressed. Specifically, as shown in FIG. 12 as in the molding step, a method of preheating while being attached to the frame 72 is preferable. When preheating is performed in this way, the sheet material 10 and 50 may be set on the cavity surface 22a of the lower mold 22 together with the frame body 72 as it is.

In the above description, the upper mold 21 is a male mold, the lower mold 22 is a female mold, and a pair of upper and lower molds in which the upper mold 21 moves up and down is illustrated as a pair of molds included in the molds 20 and 60. However, it is not limited to this.
Moreover, as long as the dam part 30 is provided according to the structure of a sheet material so that it may correspond to the discontinuous fiber layer 12 in the sheet materials 10 and 50, if it is formed in at least one of a pair of type | molds. Good.

Hereinafter, the present invention will be specifically described with reference to examples.
(1) Manufacture of discontinuous fiber layer (sheet-like material (A-1) and (A-2)) made of discontinuous fiber reinforced thermoplastic resin Carbon fiber (manufactured by Mitsubishi Rayon Co., product number: TR50S, diameter) as reinforcing fiber A bundle of 12,000 filaments having a diameter of about 7 μm was used, and polypropylene (Prime Polymer Co., J108M, melting point: 170 ° C.) was used as the thermoplastic resin to obtain a tape-like material. Specifically, first, carbon fibers were opened and impregnated with polypropylene to produce a continuous tape-like material having a volume content of reinforcing fibers (conforming to JIS K 7075) of 48%, a width of 12 mm, and a thickness of 120 μm. .
Next, this continuous tape-like material is cut into a length of 25 mm to obtain a chopped tape, the chopped tape is two-dimensionally quasi-isotropically dispersed, heated and pressed using a mold, and discontinuous fiber reinforced thermoplasticity. A square sheet (A-1) made of resin was obtained. Moreover, the rectangular sheet-like object (A-2) was obtained with the same method.
The sheet-like material (A-1) has a vertical La of 31 cm, a horizontal Wa of 4 cm, a thickness of 4 mm, and a mass of 74 g, and the sheet-like product (A-2) has a vertical La of 32 cm, a horizontal Wa of 6 cm, a thickness of 4 mm, and a mass of 115 g.

(2) Production of continuous fiber layer (sheet-like material (B-1) and (B-2)) made of continuous fiber reinforced thermoplastic resin By aligning the tape-like material produced in (1) above in one direction The obtained film-like material (length 47 cm, width 16.8 cm, thickness 120 μm) is laminated so that the fiber directions are 90 ° to each other, heated and press-molded, and a rectangular sheet-like material (B-1) is obtained. Obtained. Further, a rectangular sheet-like material (B-2) was obtained by the same method except that the number of laminated layers was five.
The sheet-like material (B-1) has a vertical Lb of 47 cm, a horizontal Wb of 16.8 cm, a thickness of 1 mm, a weight of 114 g, and the sheet-like material (B-2) has a vertical Lb of 47 cm, a horizontal Wb of 16.8 cm, a thickness of 0.6 mm, and a weight of 71 g. It is.

(3) Mold The mold 20 shown in FIG. 2 was used.
However, the weir 30 provided in the upper mold 21 is variable in height h1 between 0 and 2 mm, and the stopper S and the lower mold 22 of the upper mold 21 according to the height h1. The height h2 of the gap formed when the mold 20 is closed until it comes into contact with the stopper S is 2 to 0 mm. Moreover, the width Ws of the dam part 30 is 3 mm, and the outer edge size of the dam part 30 is Lm 40 cm long and Wm 9.5 cm wide.

[Example 1]
The sheet-like material (A-1) produced as described above is placed in an infrared heating furnace heated to 270 ° C., and after 3 minutes, the infrared heating furnace is opened and next to the sheet-like material (A-1). The sheet-like material (B-1) was put in and the infrared heating furnace was closed. After 2 minutes have passed since the sheet-like material (B-1) has been put in, these sheet-like materials (A-1) and (B-1) are taken out, the upper is the sheet-like material (A-1), and the lower is the sheet The sheet material 10 having the configuration shown in FIG.
The sheet material 10 is placed on the cavity surface 22a of the lower mold 22, and then the upper mold 21 is lowered until the stopper S of the upper mold 21 and the stopper S of the lower mold 22 come into contact with each other. After 2 minutes, the mold 20 was opened, and a molded product (thickness 2 mm) 40 ′ shown in FIG. 8 was taken out.

Prior to press molding, the upper mold 21 and the lower mold 22 were heated to 130 ° C. in advance. Further, when the mold 20 was closed, the sheet-like object (B-1) extended out of the cavity from the gap C. Further, the height h1 of the weir part and the height h2 of the gap C were both 1 mm. Since the thickness of the sheet-like material (B-1) is 1 mm, the height h2 of the gap C corresponds to 100% of the thickness of the sheet-like material (B-1).
In Example 1 as described above, the mold could be opened without any problem.

In the obtained molded product 40 ′, the portion formed from the sheet-like material (A-1) could be molded as desired and did not need to be trimmed. About the part formed from the sheet-like material (B-1), the excess part is trimmed and the final product as shown in FIG. 9 (vertical L400 mm, horizontal W95 mm, depth D25 mm, mass about 150 g) ) 40 was obtained. The mass of the part cut off from the sheet (B-1) was about 38 g.
In this molded product 40, there was a wrinkle at the corner portion of the portion formed from the sheet-like material (B-1).
Example 1 is summarized in Table 1.

[Examples 2 and 3]
A molded product was manufactured in the same manner as in Example 1 except that the height h1 of the weir portion was 1.2 mm (Example 2) and 0.8 mm (Example 3). In this case, the height h2 of the gap C is 0.8 mm (Example 2) and 1.2 mm (Example 3), which are 80% and 120% of the thickness (1 mm) of the sheet (B-1), respectively. It corresponded to.
Examples 2 and 3 are summarized in Table 1.

[Example 4]
The sheet-like material (A-1) is put into an infrared heating furnace heated to 270 ° C., and after 3 minutes, the infrared heating furnace is opened, and eight coil springs are next to the sheet-like material (A-1). The sheet-like object (B-1) attached in the frame 72 by 74 was put, and the infrared heating furnace was closed. After 2 minutes have passed since the sheet (B-1) was put in, these sheet (A-1) and (B-1) were taken out and the sheet (B-1) attached to the frame 72 The sheet material (A-1) is overlaid on top of each other to form a sheet material 10 as shown in FIG. The sheet material 10 was placed on the cavity surface 22 a of the lower mold 22. Thereafter, in the same manner as in Example 1, a molded product 40 ′ was obtained.
When the sheet material 10 is placed on the cavity surface 22a of the lower mold 22, the distance Lα shown in FIG. 13 between the lower surface of the sheet material 10 and the portion outside the cavity surface in the lower mold 22 is 10 mm. It was.
In the obtained molded product 40 ′, the portion formed from the sheet-like material (A-1) could be molded as desired and did not need to be trimmed. About the part formed from the sheet-like thing (B-1), the excess part was trimmed and the molded article 40 was obtained. The mass of the part trimmed from the sheet-like material (B-1) was about 38 g.
In this molded product 40, the portion formed from the sheet-like material (B-1) had no wrinkles and had a good appearance.
Example 4 is summarized in Table 1.

[Comparative Example 1]
A molded product was produced in the same manner as in Example 1 except that a mold having no dam portion was used. Since the used mold is not provided with a dam portion, when the mold is closed, a gap of 2 mm is generated between the upper mold and the lower mold at the outer edge of the cavity. A large amount of the sheet (A-1) flowed out from this gap. Therefore, many burrs were recognized in the molded product, and it was necessary to trim the end surface of the portion formed from the sheet-like material (A-1).
Comparative Example 1 is summarized in Table 1.

[Comparative Example 2]
A molded product was produced in the same manner as in Example 1 except that the height h1 of the weir portion was 2 mm. Since the height h1 of the weir part is 2 mm, when the mold is closed, there is no gap between the upper mold and the lower mold at the outer edge of the cavity. B-1) was firmly sandwiched and the mold could not be opened.
Comparative Example 2 is summarized in Table 1.

[Example 5]
Height of weir part h1 using sheet-like material (A-2) instead of sheet-like material (A-1), using sheet-like material (B-2) instead of sheet-like material (B-1) Is 1.4 mm, the height h2 of the gap C is 0.6 mm, and when the sheet material (A-2) is put into the infrared heating furnace after 3.5 minutes, the sheet (B-2) is put, The molded product 40 ′ was obtained in the same manner as in Example 1 except that the sheet-like materials (A-2) and (B-2) were taken out after 1.5 minutes had passed since the sheet-like material (B-2) was added. Got. The height h2 of the gap C corresponds to 100% of the thickness (0.6 mm) of the sheet-like material (B-2).
In the obtained molded product 40 ′, the portion formed from the sheet-like material (A-2) could be molded as desired and did not need to be trimmed. About the part formed from the sheet-like thing (B-2), the excess part was trimmed and the molded product (length L400mm, width W95mm, depth D25mm, mass about 150g) 40 which was a final product was obtained. The mass of the part cut off from the sheet-like material (B-2) was about 36 g.
In this molded product 40, there was a wrinkle at the corner portion of the portion formed from the sheet-like material (B-2).
Example 5 is summarized in Table 2.

[Examples 6 and 7]
A molded product 40 was produced in the same manner as in Example 5 except that the height h1 of the weir was 1.5 mm (Example 6) and 1.3 mm (Example 7). In this case, the height h2 of the gap C is 0.5 mm (Example 6) and 0.7 mm (Example 7), respectively 83% of the thickness (0.6 mm) of the sheet-like material (B-2), It corresponded to 117%.
Examples 6 and 7 are summarized in Table 2.

[Example 8]
The sheet-like material (A-2) was put into an infrared heating furnace heated to 270 ° C., and when 3.5 minutes had elapsed, the infrared heating furnace was opened, and next to the sheet-like material (A-2), The sheet-like material (B-2) attached in the frame body 72 by the coil spring 74 was put and the infrared heating furnace was closed. After 2 minutes have passed since the sheet-like material (B-2) was put in, these sheet-like materials (A-2) and (B-2) were taken out, and the sheet-like material (B-2) attached to the frame A sheet material (A-2) was stacked on top of each other to form a sheet material 10 as shown in FIG. The sheet material 10 was placed on the cavity surface 22 a of the lower mold 22. Thereafter, in the same manner as in Example 5, a molded product 40 ′ was obtained.
When the sheet material 10 was placed on the cavity surface of the lower mold 22, the distance Lα shown in FIG. 13 between the lower surface of the sheet material 10 and the portion outside the cavity surface in the lower mold 22 was 10 mm. .
In the obtained molded product 40 ′, the portion formed from the sheet-like material (A-2) could be molded as desired and did not need to be trimmed. About the part formed from the sheet-like thing (B-2), the excess part was trimmed and the molded article 40 was obtained. The mass of the part trimmed from the sheet-like material (B-2) was about 36 g.
In this molded product 40, the portion formed from the sheet-like material (B-2) had no wrinkles and had a good appearance.
Example 8 is summarized in Table 2.

[Comparative Example 3]
A molded product was produced in the same manner as in Example 5 except that a mold having no weir part was used. Since the used mold is not provided with a dam portion, when the mold is closed, a gap of 2 mm is generated between the upper mold and the lower mold at the outer edge of the cavity. A large amount of the sheet (A-2) flowed out from this gap. Therefore, many burrs were recognized in the molded product, and it was necessary to trim the end surface of the portion formed from the sheet-like material (A-2).
Comparative Example 3 is summarized in Table 2.

[Comparative Example 4]
A molded product was produced in the same manner as in Example 5 except that the height h1 of the weir was 2 mm. Since the height h1 of the weir part is 2 mm, when the mold is closed, there is no gap between the upper mold and the lower mold at the outer edge of the cavity. B-2) was firmly sandwiched and the mold could not be opened.
Comparative Example 4 is summarized in Table 2.

10, 50 Sheet material 11 Continuous fiber layer 12 Discontinuous fiber layer 21 Upper mold 22 Lower mold 23 Upper mold support plate 24 Lower mold support plate 30 Weir 40 ', 40 Molded product 74 Coil spring (elastic body)
72 Frame 71, 73 Clamp C Clearance S Stopper

Claims (11)

A method of manufacturing a fiber-reinforced thermoplastic resin molded article by pressing a sheet material in which a discontinuous fiber-reinforced thermoplastic resin layer is laminated on at least a part of one surface of a continuous fiber-reinforced thermoplastic resin layer using a mold. There,
As the mold, the outer peripheral edge of the cavity, the frame-shaped dam portion for preventing the outflow of the cavity outside of the discontinuous fiber-reinforced thermoplastic resin layer when closing the mold set vignetting, die A gap having a height of 80 to 120% of the thickness of the continuous fiber reinforced thermoplastic resin layer before press molding is formed between the front end surface of the weir portion and the outer peripheral edge of the cavity surface facing the weir portion. A method for producing a fiber-reinforced thermoplastic resin molded article, comprising a molding step of press-molding the sheet material using a mold set to be formed . The method for producing a fiber-reinforced thermoplastic resin molded article according to claim 1, wherein a height of a gap between the molds is adjustable. The method for producing a fiber-reinforced thermoplastic resin molded article according to claim 1 or 2, wherein a width of the dam portion of the mold is 1 to 20 mm. The fiber reinforcement according to any one of claims 1 to 3, wherein the reinforcing fibers contained in the discontinuous fiber-reinforced thermoplastic resin layer have a volume content of 20 to 60% and a length of 5 to 100 mm. A method for producing a thermoplastic resin molded article. The discontinuous fiber reinforced thermoplastic resin layer is formed by cutting a tape-like material having a thickness of 30 to 300 μm and a width of 5 to 30 mm in which continuous reinforcing fibers are aligned in one direction and impregnated with a thermoplastic resin into a length of 5 to 100 mm. The method for producing a fiber-reinforced thermoplastic resin molded article according to any one of claims 1 to 4 , wherein the chopped tape is dispersed and heated and press-molded by dispersing the chopped tape. The method for producing a fiber-reinforced thermoplastic resin molded article according to any one of claims 1 to 5 , wherein the reinforcing fiber contained in the continuous fiber-reinforced thermoplastic resin layer has a volume content of 30 to 70%. The continuous fiber reinforced thermoplastic resin layer is
Laminated material in which continuous reinforcing fibers are aligned in one direction and unidirectional sheet material impregnated with thermoplastic resin is laminated, and tape-shaped material in which continuous reinforcing fibers are aligned in one direction and impregnated with thermoplastic resin The cloth material according to any one of claims 1 to 6 , wherein the cloth material is made by weaving one or more members selected from the group consisting of a cloth material made by weaving and a cloth material made by impregnating a thermoplastic fiber with a reinforcing fiber fabric. The manufacturing method of the fiber reinforced thermoplastic resin molded article of description. Wherein in the molding step, the continuous fiber-reinforced thermoplastic resin layer of the sheet material attached to an elastic member provided inside the frame, the press-molding while applying tension to the continuous fiber-reinforced thermoplastic resin layer according to claim 1, The manufacturing method of the fiber reinforced thermoplastic resin molded product as described in any one of thru | or 7 . Prior to said forming step, and the discontinuous fiber-reinforced thermoplastic resin layer, wherein a preheating step of preheating the continuous fiber-reinforced thermoplastic resin layer in an infrared heating furnace separately, any of claims 1 to 8 A method for producing a fiber-reinforced thermoplastic resin molded article according to claim 1. Any one of Claims 1 thru | or 8 which has the preheating process which piles up the said discontinuous fiber reinforced thermoplastic resin layer and the said continuous fiber reinforced thermoplastic resin layer, and preheats with an infrared heating furnace before the said shaping | molding process. A method for producing a fiber-reinforced thermoplastic resin molded article according to claim 1. In the preheating step, the mounting of the continuous fiber-reinforced thermoplastic resin layer on the elastic member provided inside the frame, preheating while applying tension to the continuous fiber-reinforced thermoplastic resin layer, according to claim 9 or 10 Of manufacturing a fiber-reinforced thermoplastic resin molded article.

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